Di-quaternary acrylic monomers can be prepared from their tertiary amine by reacting it with (3-chloro-2-hydroxypropyl)trialkylammonium chloride as described in U.S. Pat. No. 4,495,367.
Polymers having monomeric units derived from di-quaternary monomers have found application in water treatment, oil-field, and consumer applications, such as, for example, as demulsifers for bitumen-containing emulsions, as described in U.S. Pat. No. 4,387,017, as hair conditioners, as described in U.S. Patent Application No. 2003/223,951, and as additives in cleaning compositions, as described in U.S. Pat. No. 6,596,261. However, known di-quaternary monomers typically contain residual non-reacted (3-chloro-2-hydroxypropyl)trimethylammonium chloride, as well as non-reacted glycidyltrialkylammonium chloride, a reaction intermediate. These impurities are difficult to separate from the monomers and thus typically end up in the polymers made from such monomers. Both of the chloride impurities are known to be toxic and their presence in such polymer products is undesirable.